In recent years, games provided to player-operated client devices, such as mobile terminal devices, by a server device over a communication network have grown popular, and many game titles have been released. These games are available in a variety of types and categories. Among such games, social games that allow multiple players to participate in the same game are especially booming. Social games that periodically or non-periodically hold a battle event (which includes not only battles, but also competitions such as team sports), in which groups battle each other, are also well known.
As an example of the latter, for example JP 2012-53640A discloses a team competition in which a plurality of players divided into two teams battle, and JP 2013-066524A discloses an online game in which, in a Coliseum hall that is a predetermined imaginary space in the game, upon matching of a plurality of parties whose members are characters controlled by players, the members of the parties battle each other.
In the field of social gaming, such a battle between groups is customarily referred to as a “guild battle” and is also referred to as “GvG”. The letter “G” represents the initial letter “G” of the word “group” or “guild”, where a “guild” generally refers to a simulation or an image of trade associations that existed in medieval European cities. The letter “v” in “GvG” stands for “versus”.
Many games that include “GvG” as a battle event have the format of a role-playing game (RPG), in which the game unfolds as a story that takes place within a consistent worldview. A representative example is a card deck RPG in which player-controlled characters that are the main actors in the RPG use a so-called deck composed of game media, such as cards. While expanding their deck by defeating opponent characters or enemy characters and making their characters grow (to a higher level), players proceed by clearing game stages such as dungeons and quests.
In addition to “GvG”, other well-known games for teams to form and compete include games in which a plurality of characters temporarily or permanently cooperate as a team and progress through the game stages of an RPG while defending the team's stronghold or territory from attack by enemy characters. Some games that adopt this format have a so-called tower defense (TD) type battle mode, allowing for increase and expansion of teams in a “wave” between game stages, and include elements and features of RPG-type games.
In both RPG type and TD type games including a conventional GvG, however, the determination of which of the groups or teams wins the battle event is often made with a simple formula. In greater detail, the winning group or team tends to be determined by, for example, (a) whether all opponent characters or enemy characters were eliminated (whether all allied characters were eliminated), (b) whether the stronghold or enemy territory of the opponent group or enemy group was invaded (whether the stronghold of one's own group or one's own army was conquered), or (c) the amount of points, at the end of the battle event, that were earned by defeating opponent characters or enemy characters.
Therefore, in order to defeat opponent characters and enemy characters, game strategy for groups or teams has mainly focused on including more highly-experienced, high-level, strong characters as group members, and on how to strengthen each character. As a result, the way battle events are fought becomes monotonous, without changing through progressive game stages. This leads to problems such as combat and other actions being sluggish during the majority of a GvG battle, and inexperienced, low-level players having difficulty participating in groups or battle events.